Soil anti-redeposition agents,their use and detergent compositions containing same

ABSTRACT

A PROCESS FOR THE PREVENTION OF REDEPOSITION OF SOIL DURING THE LAUNDERING PROCESS BY THE USE OF ANTI-REDEPOSTITION AGENTS, E.G., AN INOIC COMBINATION OF DODECYLTRIMETHYLPHOSPHONIUM CHLORIDE AND SODIUM CARBOXYMETHYLCELLULOSE, AND DETERGENT COMPOSITIONS CONTAINING SAID ANTIREDOPOSITION AGENTS ARE DISCLOSED.

United States Patent Oifice 3,597,416 Patented Aug. 3, 1971 U.S. Cl. 260-212 8 Claims ABSTRACT OF THE DISCLOSURE A process for the prevention of redeposition of soil during the laundering process by the use of anti-redeposition agents, e.g., an inoic combination of dodecyltrirnethylphosphonium chloride and sodium carboxymethylcellulose, and detergent compositions containing said antiredoposition agents are disclosed.

This invention concerns the prevention of redeposition of soil on fabrics during the laundering cycle. More particularly, it concerns the prevention of redeposition of soil on a broad spectrum of fibers and fabric types encountered in the usual laundering cycle. Such fiber and fabric types range from the hydrophilic types such as cloth woven from cotton, linen or rayon fibers to less hydrophilic materials such as resin-treated cotton fabrics, the so-called permanent press fabrics, to hydrophobic types of fabrics such as cloth woven from polyester, nylon, acrylic and blends of these fibers. This invention concerns a composition of matter effective in preventing soil redeposition on a wide range of fabric types. In addition this invention concerns a process for improving the detergency of detergent compositions wherein compositions of matter, as antiredeposition agents, have been employed.

As is well known in the art, as fabrics are washed, soil is removed from the fiber and becomes suspended in the wash water. Soil removal is accomplished by a combination of factors; for example, some of these factors are the mechanical action of water, the wetting action of the Water, the temperature of the water, the action of organic detergents or soaps and the action of detergency builders. Inherent in the washing procedure, however, is the redeposition of soil suspended in the wash water onto the surface of the fabrics being laundered. The redeposition of soil suspended in the water onto the fabric occurs on all types of fabrics, e.g., cotton, nylon, polyester, and blends of these fibers.

The degree of redeposition of the suspended soil varies with the character of the fabric which in turn is somewhat dependent on the types of fiber making up the fabrics. Soil is normally hydrophobic. The more hydrophilic the surface of the fiber being washed, the less is the redeposition of the soil suspended in the wash water; conversely the more hydrophobic the surface of the fiber being washed, the greater is the redeposition of soil. It is well known in the art that soil redeposition during laundering does occur and to minimize this a number of antiredeposition agents or redeposition inhibitors have been found which are effective on cotton fabrics. (The terms anti-redeposition agent and redeposition inhibitor are used in the art and hereinafter interchangeably.) The best known anti-redeposition agents effective on cotton are carboxymethylcellulose and carboxymethylhydroxyethylcellulose and these materials are used in detergent compositions to minimize redeposition of soil on cotton fabrics.

However, as is well known in the art, fabrics which are Woven from hydrophobic fibers such as those woven from polyester fibers, the most common of which are basically copolymers of ethylene glycol and terephthalic acid and are sold under a number of trade names, e.g., Dacron, Fortrel, Kodel and Blue C Polyester, or fabrics which are blends of polyester fibers and cotton fibers (e.g., 65% polyester/35% cotton) tend to become gray on repeated laundering. The anti-redeposition agents which are effective on cotton are substantially less effective on polyester fibers. This graying effect of the polyester fiber is attributed to the inherent nature of the fiber. Soil is redeposited on the surface of the polyester fiber from the wash solution during the Washing process just as it is with cotton. Anti-redeposition agents effective on cotton do not minimize redeposition of soil on polyester fabrics nor on fabrics containing a high percentage of polyester content.

As a result of the tendency of hydrophobic fabrics to gray and the inability of known anti-redeposition agents to prevent redeposition of soil on such fabrics completely, manufacturers of the basic fibers and of the fabrics have sought to change the nature of the fiber itself through the use of additives, padding baths or other fiber modification techniques to prevent, or at least minimize, this graying effect. For example, with polyesters numerous fiber modification techniques to make the base fiber more hydrophilic have been described in the art. In Netherlands application 6509456, a polymer of terephthalic acid and polyethylene glycol was padded onto the polyester fabric in a 20% concentration using a polyester swelling agent such as benzyl alcohol, benzaldehyde or o-phenylphenol. This was in an effort to give the basic fiber more hydrophilic character and to reduce redeposition of soil onto polyester fabrics and polyester/cotton blends during washing.

Other fabric finishing techniques can be found in the art for modifying the inherent hydrophobic nature of the polyester fiber. For example, German Patent 1,194,363 describes the use of a polyethylene glycol-itaconic acid polymer for use as an antistatic agent for synthetic fibers to reduce soil pickup. Netherlands application 6502428 and Belgian Patent 641,882 describe the treatment of polyester fabrics with polyethylene glycol to increase its hydrophilic character. In addition, French Patent 1,394,401 describes the treatment of polyester with an alcohol or glycol in the presence of a strong nonvolatile acid to increase the hydrophilic character of the polyester fiber.

Other approaches have been used in the art to increase the effectiveness of detergent compositions in which carboxymethylcellulose is used. Wixon in U.S. Patent 3,360,- 470 discloses mixtures of a quaternary ammonium compound such as dimethyl ditallow ammonium chloride and sodium carboxymethylcellulose.

Such combinations of a softening agent and an antiyellowing agent are to be used in the wash or rinse cycle of the laundering process.

Other approaches have primarily used carboxymethylcellulose in admixture with its derivatives, e.g., carboxymethylhydroxyethylcellulose, and with other non-cellulosic materials to impart different properties to detergent compositions: TroWbridge in U.S. Patent 3,318,816 discloses the use of carboxymethylcellulose with polyvinylpyrrolidone as a soil suspending agent in a detergent composition; Morris in U.S. Patent 3,335,086 discloses the use of carboxymethylcellulose and a substantially linear hydrocarbon polymer having hydroxyl and carboxyl substituents which act to prevent redeposition of soil; Inamorato in U.S. Patent 3,265,624 discloses the use of carboxymethylcellulose and polyvinyl alcohol as soil suspending agents during washing; Brunt et al. in U.S. Patent 3,044,962 disclose the use of a quaternary ammonium compound (also phosphonium and morpholinium com- 3 pounds) in detergent compositions as having anti-redeposition properties during washing.

As can be seen from the prior art hereinbefore described, a number of approaches have been taken toward either changing the hydrophilic/hydrophobic nature of the fiber or fabric or using additives in detergent compositions to prevent redeposition. The approaches which have been used to minimize redeposition of soil are those which are effected by the fiber or textile manufacturer or which use carboxymethylcellulose in admixture with other ma terials.

This invention then concerns effective redeposition inhibitors, i.e., those that are effective on both cotton fabrics and on a wide range of fabric types such as polyester, nylon, acrylics and polyester/cotton blends. In addition this invention concerns effective anti-redeposition agents which are particularly effective when used to prevent the problem of graying of polyester and polyester/cotton blend fabrics. This invention also concerns anti-redeposition agents formed by a combination of two materials which prevent redeposition of soil on a wide range of fabric types. In addition, this invention concerns detergent compositions containing the redeposition inhibitors of this invention which are effective both on cotton and on a wide range of fabric types.

The redeposition inhibitors which are effective in preventing soil redeposition are characterized as being ionic combinations of the following formula CHZOZ wherein A is a positively charged component selected wherein R is an alkyl, aralkyl, alkaryl, alkoxyalkyl, alkylaryloxyalkyl, N-acylaminoalkyl, or cyclic alkyl group having from 10 to 22 carbon atoms; wherein each R R and R is selected from the group consisting of (a) an alkyl group having from 1 to 3 carbon atoms, (b) a hydroxyalkyl group having from 1 to 3 carbon atoms, (0) phenyl, (d) benzyl, (e) a polyethenoxy group having from 1 to 50 repeating ethenoxy units, and (f) a polypropenoxy group having from 1 to 10 repeating propenoxy units; wherein Q is selected from the group consisting of nitrogen, phosphorus, sulfur and sulfoxide; wherein y is 1 if Q is nitrogen or phosphorus and 0 if Q is sulfur or sulfoxide; and (2) a heterocyclic quaternary nitrogen nucleus selected from wherein R is as hereinbefore defined and wherein each R and R is selected from the class consisting of alkyl groups having from 1 to 3 carbon atoms, hydroxyalkyl groups having from 1 to 3 carbon atoms, polyethenoxy groups having from 1 to 50 repeating ethenoxy units, and polypropenoxy groups having from 1 to 10 repeating propenoxy units, wherein each Z is selected from the group consisting of hydrogen, carboxymethyl, sulfato, phosphato, phosphonomethyl, sulfoethyl, sulfopropyl, sulfohydroxypropyl, hydroxyethyl, acetyl, a polyethenoxy group having from 1 to 50 repeating ethenoxy units, and a polypropenoxy group having from 1 to 10 repeating propenoxy units; wherein p is n times the summation of the products of a and s, wherein n indicates the degree of polymeriza ion and ranges from about 100 to about 2000; wherein s is the average degree of substitution at the Z positions of substituents other than hydrogen, said degree of substitution for substituents resulting in a negative charge at the Z positions ranging from about 0.1 to about 2.0 and said degree of substitution for substituents resulting in no charge at the Z positions ranging from O to about 2.9; wherein oz is the net charge obtained with the groups substituted at the Z positions.

The redeposition inhibitors described b the formula shown above are characterized as ionic combinations. The term ionic combination as used herein to describe the nature of the redeposition inhibitors of this invention means an ionic association of a large bulky positively charged group A, with a negatively charged polymeric cellulose derivative (for which the basic monomeric building block of cellulose is shown). When a solution containing the positively charged component, e.g., dodecyltrimethylammonium chloride, is mixed with a solution containing the negatively charged component, e.g., sodium carboxymethylcellulose, a metathesis occurs resulting in the ionic association, e.g., dodecyltrimethylammoniumcarboxymethylcellulose, of the negative cellulose derivative with the positive group A. The counterions associated with the positive group, e.g., chloride, and the negative group, e.g., sodium, because of their salt-like characteristics, e.g., sodium chloride, remain ionized in the solution containing the redeposition inhibitors.

Where R in A above is an alkyl group, suitable alkyl groups are as follows: decyl, dodecyl, tetradecyl, pentadecyl, hexadecyl, octadecyl, eicosyl, and docosyl. Where R is an aralkyl group, suitable groups are as follows: phenylbutyl, biphenylethyl, phenyldodecyl, phenylhexadecyl, biphenyldecyl, and phenyltetradecyl. Where R is an alkaryl group, suitable groups are as follows: dodecylphenyl, hexadecylphenyl, tetradecylphenyl, pentadecylphenyl, decylphenyl, and dodecylphenyl. Where R is the cyclic alkyl group, suitable groups are as follows: cyclododecyl, cyclopentadecyl, and cycloeicosyl. Dodecyl, tetradecyl, hexadecyl, and octadecyl are preferred. Where R is an alkoxyalkyl group, suitable groups are methoxydodecyl, ethoxydodecyl, dodecoxyethyl, and pentadecoxypropoyl. Where R is an alkaryloxyalkyl group, suitable groups are butylphenoxyethyl, octylphenoxybutyl, and ethylphenoxytridecyl. Where R is an N-acylaminoalkyl group, suitable groups are N-acetylaminopentadecyl, N-dodecanoylaminobutyl and N-octanoylaminodecyl Where R R and R in A above are alkyl groups, suitable alkyl groups are methyl, ethyl, and propyl and are preferred. Where R R and R are hydroxyalkyl groups, suitable groups are hydroxymethyl, hydroxyethyl, and hydroxypropyl. Hydroxymethyl and hydroxyethyl are preferred. Where R R and R in A above are polyethenoxy or polypropenoxy groups, the preferred polyethenoxy group contains from about 2 to about 25 repeating ethenoxy units and the preferred polypropenoxy group contains about 2 to about 5 repeating propenoxy units.

Benzyl and phenyl are suitable for R R and R and are also preferred.

Q in the above formula can be nitrogen, phosphorus, sulfur and sulfoxide. The positively charged group formed Where Q is nitrogen, phosphorus, sulfur and sulfoxide are respectively ammonium, phosphonium, sulfonium, and sulfoxonium groups.

Specific examples of compounds which provide the positively charged group A, employed in forming the redeposition inhibitors of this invention are as follows: dodecyltrimethylammonium chloride, di(2-hydroxyethyl) methyloleylammonium iodide, cetyltrimethylammonium bromide, ethyldimethyloctadecylammonium methyl sulfate, dimethylpropyltetradecylammonium acetate, trimethylstearylphosphonium bromide, cetylethylmethylpropylphosphonium iodide, triethyloleylphosphonium chloride, decylpolyethenoxydipropylammonium chloride, dodecylethyldimethylphosphonium methyl sulfate, dipolypropenoxymethyltetradecylphosphonium, iodide, hexa;

U decyldirnethylphenylammonium acetate, (dodecylphenyl) triethylphosphonium chloride, cyclotetradecyltrimethylphosphonium methylsulfonate, ethylmethyloctadecylsulfoxonium bromide, methyloctadecylpropylsulfoxonium iodide, (dodecylphenyl)dimethylsulfoxonium chloride, (3- hydroxypropyl)-rnethyloleylsulfoxonium acetate, ethylmethyltetradecylsulfoxonium methyl sulfate, (hydroxyethyl)methyl(phenyltridecyl)sulfoxonium acetate, dodecyldimethylsulfoxonium iodide, dimethyltetradecylsulfoniumbromide, ethylmethyltetradecylsulfonium chloride, cetyldimethylsulfonium acetate, cetylethylpropylsulfonium ethyl sulfate, dodecylidi(hydroxymethyl)sulfonium ethylsulfonate, bis[(2,3 dihydroxypropyl)methyltetradecylsulfonium] sulfate.

The ammonium, phosphonium, and sulfoxonium groups wherein R contains from about 12 to about 18 carbon atoms, preferably dodecyl and octadecyl where these are derived from coconutalkyl and tallowalkyl groups, are preferred. The preferred R R and R groups are methyl, ethyl, and hydroxyethyl. Also preferred for R R and R ae polyethenoxy groups where there are about 2 to about 25 repeating ethenoxy units, The counter-ion, associated with the positively charged group A, can be chloride, bromide, iodide, sulfate, alkylsulfonate, alkyl sulfate, acetate and hydroxyl. Chloride, bromide and methyl sulfate are the preferred counterions.

The positively charged group A, can be formed from a compound containing a heterocyclic nitrogen nucleus. In the formulas given above for the heterocyclic nitrogen nuclei which are suitable for A, only a portion of the structural formula for the heterocyclics is given. Formulas a and b describe heterocyclics involving both single ring and condensed ring systems. Formula a describes the double bonded nitrogen species and Formula b describes the single bonded nitrogen species. In Formulas a and b the long chain R and the short chain groups R and R are bonded to the nitrogen atom in the heterocyclic nucleus. Formulas c and (1 describe heterocyclic nitrogen nuclei involving both single ring and condensed ring systems. In Formulas c and d the long chain R group is substituted in the ring system other than at the quaternary nitrogen atom while the short chain alkyl groups R and R are bonded to the nitrogen atom.

Where A above is formed from a compound containing a heterocyclic nitrogen nucleus, the nucleus of the quaternary group so formed can be pyridine, imidazoline, morpholine, pyrrolidine, pyrroline, piperidine, piperazine, indoline, imidazolidine, quinoline, indole, pyrimidine, pyrazine, pyrrole, and triazine. When the above mentioned heterocyclics are quaternized they give rise to the ium" groups, e.g., pyridinium, imidazolinium and morpholinium groups.

R in the above heterocyclic nitrogen groups can be dodecyl, decyl, heXadecyl, tetradecyl, pentadecyl, octadecyl, eicosyl, docosyl, coconutalkyl and tallowalkyl. Dodecyl, hexadecyl, and octadecyl are preferred. Suitable groups for R and R are methyl, ethyl, propyl, hydroXymethyl, hydroxyethyl, and hydroxypropyl. Methyl, ethyl, hydroxymethyl and hydroxyethyl are preferred.

Specific examples of compounds containing a heterocyclic nucleus, suitable for use as the positively charged group (A), are as follows: dodecylpyridinium chloride, hexadecylmethylimidazolinium bromide, ethyltetradecylmorpholinium chloride, octadecylpropylpyn'olidinium iodide, Inethylpentadecylpyrrolinium methyl sulfate, eicosylethylpiperazinium ethylsulfonate, docosylquinolinium acetate, heptadecylpyrimidinium bromide, N-methyl-2-dodecylpyridinium chloride, N-hydroxyethyl-N-ethyl-Z- pentadecylimidazolinium methyl sulfate, hexadecyltriethenoxymorpholinium chloride and bis(tetradecylpyridinium) sulfate. Compounds involving the pyridine, imidazoline and morpholine nucleus are preferred.

The cellulose derivative used with the positively charged group A, in forming the redeposition inhibitors of this invention can be substituted with a number of different groups at the Z positions. It should be understood that where no substitution occurs at a particular Z position, a hydrogen atom will occupy that position. That is to say, substitution by any group at a Z position will displace a hydrogen. The maximum average degree of substitution of the cellulose derivative is 3 and where the average degree of substitution is less than 3, the average degree of non-substitution (i.e., the average number of hydrogens retained at the Z positions) is the difference between 3 and the average degree of substitution; for example, if a carboxymethylcellulose has an average degree of substitution of 2, on the average 2 of the Z positions will contain carboxymethyl groups and on the average 1 of the Z positions will contain hydrogen. More specific descriptions of the cellulose derivatives are given hereinafter. Where carboxymethyl and hydrogen are the substituents at the Z positions in the cellulose derivative, the cellulose derivative is carboxy'methylcellulose; where sulfato and hydrogen are the substituents at the Z positions, the cellulose derivative is cellulose sulfate; where carboxymethyl, hydrogen and hydroxyethyl are the substituents at the Z positions, the cellulose derivative is carboxymethylhydroxyethylcellulose where acetyl and sulfato are the substituents at the Z positions, the cellulose derivative is cellulose acetyl sulfate; where phosphato and hydrogen are the substituents at the Z positions, the cellulose derivative is cellulose phosphate; where phosphonomethyl and hydrogen are the substituents at the Z positions, the cellulose derivative is phosphonomethylcellulose; where sulfoethyl and hydrogen are the substituents at the Z positions, the cellulose derivative is sulfoethylcellulose; where sulfopropyl and hydrogen are the substituents at the Z positions, the cellulose derivative is sulfopropylcellulose; where sulfohydroxypropyl and hydrogen are the substituents at the Z positions, the cellulose derivative is sulfohydroxypropylcellulose; and where polyethenoxy or polypropenoxy, hydrogen and carboxymethyl are the substituents at the Z positions, the cellulose derivative is a polyethenoxycarboxymethylcellulose or a polypropenoxycarboxymethylcellulose.

The preferred cellulose derivatives used in forming the redeposition inhibitors of this invention are carboxymethylcellulose, carboxymethylhydroxyethylcellulose, cellulose sulfate, cellulose acetyl sufate, phosphonomethylcellulose, sulfoethylcellulose, and polyethenoxycarboxymethylcellulose.

In the above formua for the negatively charged cel lulose derivative, 11 indicates the degree of polymerization of the cellulose derivative and ranges from about to about 2000. It is preferred that the range of n be from about 500 to about 1500.

The groups which are suitable for use at the Z positrons can result in either a negative charge or no charge at the Z positions, i.e., the substituents at each Z position can give rise to a negative charge or no charge at that position depending on the character of the substituent occupying that position. For example, where a carboxymethyl group, CH COO, replaces a hydrogen at one of the Z positions, a negative charge results at that position. Where a hydroxyethyl group, CH CH OH, replaces a hydrogen at one of the Z positions, no charge results at that position. For the groups which have been hereinbefore described as suitable as substituents at the Z positions, those substituents which result in a negative charge are carboxymethyl, sulfato, phosphato, phosphonomethyl, sulfoethyl, sulfopropyl, and sulfohydroxypropyl; and those substituents which result in no charge are hydrogen, hydroxyethyl, acetyl, polyethenoxy and polypropenoxy. As hereinbefore described s is the average degree of substitution at the Z positions. The degree of substitution s, of substituents resulting in a negative charge can range from about 0.1 to about 2.0. The preferred range of this degree of substitution is from about 0.2 to about 1.2. The degree of substitution for substituents resulting in no charge is from to about 2.9, preferably from about 0 to about 2.0. The sum of the charges generated by the substituents at the Z position in each monomeric unit in the cellulose polymer gives the cellulose derivative its ionic (negative) characteristics. The negatively charged characteristics of the cellulose derivative interact with the positively charged characteristics of the group A to form the ionic combinations as hereinbefore described.

In the description of the cellulose derivatives which are suitable for use as the negatively charged components of the redeposition inhibitors of this invention, it is apparent some of the Z positions in the cellulose derivative (that is, some of the Z positions along the polymer chain) must contain substituents which will result in a negative charge. There may be other Z positions occupied by substituents which result in a negative charge or which result in no charge at those positions. Where all of the Z positions in the cellulose polymer contain substituents which result in no charge at the Z positions, the cellulose derivative is an electrically neutral cellulose derivative. An electrically neutral cellulose derivative is not suitable for the purposes of this invention since an electrically neutral cellulose derivative will not interact with the positively charged group A to form the redeposition inhibitors of this invention. Upon examination of the spe cific examples of the cellulose derivatives described hereinbefore as suitable for the purposes of this invention, it can be seen that those derivatives which contain a group yielding no charge when substituted at the Z positions in the cellulose derivative also contain a group which yields a negative charge 'when substituted at the Z positions in the cellulose derivative, e.g., carboxymethylhydroxyethyl cellulose and cellulose acetyl sulfate.

The redeposition inhibitors of this invention are formed by the interaction of the two components as the ionic combination, e.g., the ammonium, heterocyclic ammonium, phosphonium, sulfonium or sulfoxonium containing compound (the positively charged component) and the cellulose derivative (the negatively charged component). Aqueous solutions of each component are normally used and the two components are premixed to form the redeposition inhibitors prior to use. The sodium and potassium salts of the cellulose derivative employed are commonly used although the associated counterions with the cellulose derivative can be hydrogen, ammonium, lithium and substituted ammonium (mono-, diand trialkyl ammonium and hydroxyalkyl ammonium). The chlorides, bromides and methyl sulfates of the positively charged component are normally used although the associated counterions hereinbefore mentioned can be used where desired. It is to be understood that the mixing of the positively and negatively charged components to prepare the redeposition inhibitors, their associated counterions will also be present in the mixture containing the redeposition inhibitors. These counterions do not interfere with the effectiveness of the redeposition inhibitors in preventing soil redeposition. The premixing of the two components is necessary to obtain etfectiveness in preventing redeposition of soil during the laundering of textiles. The ratio of the components making up the redeposition inhibitors is normally equivalent amounts (i.e., an amount of each component which will satisfy the ionic charges of the other component to result in an electrically neutral ionic combination) of the ammonium, heterocyclic ammonium, phosphonium, sulfonium, or sulfoxonium positively charged portion and the negatively charged cellulose derivative. Equivalent amounts of the two components are preferred to obtain maximum advantage in preventing soil redeposition on a wide range of fabric types. However, excess cellulose derivative can be used in a molar ratio of up to to 1 to the positively charged component and excess ammonium, heterocyclic ammonium, phosphonium, sulfonium and Sulfoxonium component can be used in a molar ratio of up to 1.1 to 1 to the cellulose derivative. Thus, the molar ratio of the negatively charged component to the positively charged component can range from about 10:1 to about 1:1.1. The redeposition inhibitors formed are effective regardless of whether an excess of either component is used. The interaction in the formation of the redeposition, inhibitors is normally evidenced by the appearance of a solution cloudiness or turbidity which is normally dispersible with agitation. The premixing step can be accomplished with any of the methods known in the art for combining ingredients. The pre-mixing step is necessary regardless of whether the redeposition inhibitor is to be added separately to the wash water or preferably as an ingredient of a detergent composition for use in laundering textiles.

The redeposition inhibitors as defined above are effective alone or preferably in combination with a wide number of organic detergents, detergency builders, and other materials typically used in detergent compositions such as corrosion inhibitors, color, perfume, fluorescers, enzymatic cleaning agents, and inorganic filler materials.

The detergent compounds which can be used in combination with these anti-redeposition agents herei-nbefore described are the true soaps and synthetic detergents, which include the classes of anionic, nonionic, zwitterionic and ampholytic synthetic detergent compounds and mixtures of these synthetic detergent compounds.

The detergents suitable for use in the detergent compositions employing the redeposition inhibitors of this invention, hereinbefore described, are outlined at length in U.S. Pat. 3,308,067, issued Mar. 7, 1967, to Francis L. Diehl, Column 7, line 8 to Column 9, line 26. The detergents disclosed therein are suitable for the purposes of this invention, either individually or mixtures thereof, and are incorporated herein by reference.

The compounds generally described as builders and whose function is to increase the detergency effectiveness of the hereinbefore-mentioned detergents are numerous in scope. Included within this class of detergency builders are the typical water-soluble inorganic alkaline builder salts such as the alkali metal tripolyphosphates, pyrophosphates, orthophosphates, perborates, tetraborates, hexaphosphates, sesquicarbonates and bicarbonates, and mixtures thereof. In addition, the water-soluble organic alkaline builder salts such as amino polycarboxylates and the polyphosphonates can also be used. The above-mentioned water-soluble organic alkaline builder salts are disclosed in U.S. Pat. 3,351,558, issued Nov. 7, 1967, to Roger B. Zimmerer, Column 3, lines 1 to 30, and are incorporated herein by reference.

A tarnish inhibitor such as benzotriazole or ethylenethiourea can be added in amounts up to 2% by weight to prevent tarnishing of German silver. Fluorescers, perfume, enzymatic cleaning agents and color, while not essential to the invention, can be added in amounts up to about 1% by weight. Inorganic filling agents, such as sodium sulfate, and water can also be present in the detergent compositions of this invention.

The anti-redeposition agents of this invention will perform effectively alone when used at a wash-water concentration of from 1 p.p.m. to 10,000 p.p.m. by being added separately to the wash water in addition to the normal use of a detergent composition. Below a washwater concentration of 1 p.p.m. little advantage is seen in preventing redeposition of soil and with a wash-water concentration of more than 10,000 p.p.m. the advantage obtained is not warranted from a cost standpoint. The preferred wash-water concentration range is from about 3 p.p.m. to about 2000 p.p.m. to balance effectiveness and cost. In addition to the use of the anti-redeposition agents alone, they can be advantageously and preferably incorporated in a detergent composition consisting of those components hereinbefore mentioned.

The anti-redeposition agents, hereinbefore described, when used alone can be in the form of a powder, gel or dilute aqueous solution, or when used in combination with the detergent components, hereinbefore described, can be formulated into any of the several commercially desirable composition forms; for example, granular, flake, liquid, bar and tablet forms.

According to one embodiment of the present invention, a built detergent composition can be prepared consisting essentially of an organic synthetic detergent selected from the group consisting of anionic, nonionic, amphoteric, and zwitterionic detergents and mixtures thereof, and a detergency builder selected from the group consisting of water-soluble inorganic alkaline builder salts, Water-soluble organic alkaline builder salts and mixtures thereof, the ratio of said organic detergents to said detergency builders being in the range of about :1 to about 1:20 by weight. From about 0.01% to about 10% by weight of an anti-redeposition agent of the present invention is normally used from the standpoint of a balance between effectiveness in preventing soil redeposition and cost. A preferred range for the weight ratio of the organic detergents to the detergency builder is from about 5:1 to about 1:10 by weight, and the preferred level of the anti-redeposition agent is from about 0.01% to about 2.0% by weight. Water-soluble alkali metal silicates, although not a part of this invention, having a ratio of SiO :M O of from about 1.0 to about 3.6, preferably from 1.6 to 3.2, (wherein M in the above ratio is selected from the group consisting of potassium and sodium) up to about by weight, with the preferred range being about 5% to about 15%, of the built detergent composition, can also be employed as a part of the built detergent composition.

More specifically, where designed as a typical detergent composition for use in heavy-duty laundering at normal usage, the detergent composition employing the anti-redeposition agents of this invention can consist essentially of:

(1) From about 10% to about by weight of an organic detergent selected from the group consisting of nonionic, anionic, ampholytic, and zwitterionic detergents, and mixtures thereof,

(2) From about 0.01% to about 10% by weight of an anti-redeposition agent hereinbefore described,

(3) From about 10% to about 60% by weight of a detergency builder selected from the group consisting of water-soluble organic alkaline builder salts, watersoluble inorganic alkaline builder salts, and mixtures thereof;

of oleic acid, olive oil and light mineral oil), 0.002% particulate soil recovered from air conditioning filters, and 0.085% of a built detergent formulation [20% sodium alkyl (C benzenesulfonate (ABS), sodium tripolyphosphate and 20% sodium sulfate] in water containing 10 gr./gal. hardness (calcium carbonate equivalent).

Samples of the redeposition inhibitors to be used in the simulated laundry water suspension to demonstrate antiredeposition properties on a wide range of fabric types were prepared from the compounds containing the positively charged components and cellulose derivatives shown in Table I below.

TABLE I [Description of the compounds and the cellulose derivatives containing the positively and negatively charged components used in preparing the anti-redepositlon agents] Associated Designation Positively charged component eounterion A Dodecyltrimethylphosphonium Chloride.

Dodeeyldimethylsulioxonium Methyl sulfate.

Methyldi (polyethenoxy) octadecylam- Chloride.

monium (polyethenoxy group=15 total ethenoxy units). Cetyltrimethylammonium Bromide. Cetylpyridinium Chloride. Benzyldimethyl[1nethyl-4(1,l,3,3 tetra- Do.

methylbutyl) phenoxyethoxyethyllammonium.

G Benzyldodecyldimethylammonium Do.

Negatively charged component Carboxymethylcellulose (8=D.67) Sodium.

Ihosphonomethylcellulose (8 029) Disodium. Cellulose acetyl sulfate (8=(].96 for sulfate Sodium.

and 1.61 for acetyl). Sulfohydroxypropyl cellulose (s=0.56)...-- Do.

M Carboxymethylhydloxyethylcellulose(s: Do.

0.4 for carboxymethyl and 0.3 for hydroxyethyl).

N Carboxymethylcellulose (s=0.50) Do.

1 Cellulose acetyl sulfate (9:062 for sulfate Do.

and 1.90 for aeetyl).

The anti-redeposition agents used in the following examples were prepared by premixing 10 ml. of a solution containing the positively charged component with 10 ml. of a solution containing the negatively charged cellulose derivative. In each instance, the formation was evidenced by cloudiness or solution turbidity which was an indication of the ionic association taking place between the positively charged component and the negatively charged component. The anti-redeposition agents formed from the positively charged components and the cellulose derivatives of Table I and used in Examples I to VII are shown in Table II below.

TABLE II.ANTIREDEPOSITION AGENTS Positively charged component solution Weight of the compound Cellulose derivative solution Compound containing the containing positively Weight of positively charged Volume of cellulose Volume of charged component distilled Cellulose derivative distilled Example No. component (g) water (ml) derivative (g) water (ml.)

(4) From 5% to about 15% by weight of an alkali metal silicate; and

(5) From 0% to about 74.99% by weight of Water.

All parts, percentages and ratios hereinbefore and hereinafter used are by weight unless otherwise specified.

EXAMPLES A simulated used laundry-water suspension, was prepared by mixing together 0.02'% oil (equal volumes previously, to yield one liter of simulated washing solution for each example (for Examples I to VII). For Example VIII, 980 ml. of simulated used laundry water suspension plus 20 ml. of distilled water, without any added anti-redeposition agent, to yield 1 liter was used as the control.

Five clean squares x 5") each of cotton, nylon, polyester, 65% polyester/ 35% cotton (resin-finished) and acrylic fabrics were agitated in the one liter of used simulated laundry Water suspension in a miniature washer (Tergotometer) for 20 min. at 120 F. for each of the eight examples (the seven treatments plus the blank). The fabrics were then rinsed twice at 120 F. for two minutes each in clean water of 1 0 gr./gal. hardness;

Subsequently, the fabrics were dried and the procedure repeated for a total of four cycles. The degree of lightness of the fabrics due to reflected light was measured with a Hunter Color Difference Meter, Model D-25.

, The lightness results obtained are summarized in Table III below for Examples I to VII, in which antiredeposition agents were used, versus Example VIII, the blank containing no anti-redeposition agent.

12 inhibitors were effective in preventing even this small amount of soil from redepositing. In this case the effectiveness of the redeposition inhibitors is shown more readily by the percent Inhibition. Both the Fabric Lightness Values and the percent Inhibition demonstrate that the anti-redeposition agents are effective in preventing soil redeposition during laundering on all types of fabrics.

When in Examples I to VII above other compounds containing positively charged components replace on an equivalent basis the compounds containing the positively charged components to form the anti-redeposition agents in Examples I to VII (see Table II), substantially equivalent results are obtained in that redeposition of soil on fabrics during laundering is minimized. Examples of compounds which can be used to replace those used in Examples I to VII are set forth in greater detail in Cols. 4 and 5 of the specification.

When in Examples I to VII above other cellulose derivatives replace on an equivalent basis the cellulose derivatives used in forming the anti-redeposition agents in Examples I to VII (see Table II), substantially equiva- Fabric lightness values (AL) Soil anti-redeposition (percent inhibition) 65 poly- 65 polyester/ ester/35 Cotton Polyester Nylon cotton Acrylic Cotton Polyester Nylon cotton Acrylic The results summarized above in Table III show the advantage gained in fabric lightness when an anti-redeposition agent was used over that obtained when no anti-redeposition agent was used. The AL shown is the lightness 'value of the fabric sample minus the lightness value of a corresponding fabric sample washed only in the blank (i.e., no added anti-redeposition agent). On examination of the results shown above, it can be seen that a lightness advantage is gained on all fabric types when an anti-redeposition agent is used over that when no anti-redeposition agent is used.

The degree of soil redeposition inhibition is also shown in Table III above for each example. The degree of soil redeposition inhibition on a percentage basis was calculated using the following relationship LEI-LB o B wherein L is the lightness value of the fabric sample washed in an experimental treatment containing an antiredeposition agent, L is the lightness value of a corresponding fabric sample as it originally appeared before being washed, and L is the lightness value of a corresponding fabric sample washed in the blank.

On examination of the results showing the degree of inhibition summarized in Table III above, it can be seen that the anti-redeposition agents used were effective in inhibiting soil redeposition on all types of fabrics.

Both Fabric Lightness Values and the percent Inhibition are shown in Table III for the different fabric types. The Fabric Lightness Values demonstrate that on every fabric type an advantage is shown where the redeposition inhibitor is used over that obtained with the control. With the more hydrophilic fibers, the relative change in AL is larger than with the less hydrophilic fabric types. This is reflected in the percent Inhibition values. With a fabric such as an acrylic fabric, only a small amount of soil redeposits resulting in a small AL. The redeposition Percent Inhibition X 100 lent results are obtained in that redeposition of soil on fabrics during laundering is minimized. Examples of cellulose derivatives which can be used to replace those used in Examples I to VII are set forth in greater detail on page 13, line 9, to line 28, of the specification.

EXAMPLE IX The following detergent compositions are prepared by mixing the following components in the amounts specified.

Composition, percent Component A B C D Sodium tallowalkyl sulfate 40 35 30 25 Sodium tripolyphosphate... 45 50 55 60 Anti-redeposition agent 1 3 6 1 0 Water Balance An ionic combination of cetyltrimethyl ammonium-sulfo-hydroxypropylcellulose as prepared in Example IV.

When any of the above four detergent compositions is used in laundering textiles, redeposition of soil on fabrics is minimized.

EXAMPLE X The following detergent compositions are prepared by mixing the following components in the amounts specified.

Component E F G H Sodium hexadecyl benzene sulfonate 25 30 25 35 Dodecyldlmethyl amine oxide. 10 10 15 5 Sodium tripolyphosphate 60 55 50 45 Anti-redeposition agent* 0. 01 0. 1 1 10 Water Balance 100 or in part, the sodium tallowalkyl sulfate used in Example IX above or the sodium hexadecyl benzenesulfonate used in Example X above, substantially equivalent results are obtained in that soil redeposition on fabrics is minimized: e.g., anionic detergents such as sodium and potassium alkyl benzene sulfonates, sodium coconutalkyl sulfate, tallowalkyl glyceryl ether sulfonates; nonionic synthetic detergents such as the condensation product of ethylene oxide with the condensation product of propylene oxide and propylene glycol, the condensation product of coconutalk-yl fatty alcohol with 15 moles of ethylene oxide per mole of alcohol, dodecyldimethylamine oxide, tetradecyldimethylphosphine oxide, and dodecyl methyl sulfoxide; ampholytic synthetic detergents such as sodium 3-dodecylaminopropionate and sodium 3-dodecylaminopropane-l-sulfonate, and zwitterionic synthetic detergents such as 4-[N,N-di(2-hydroxyethyl) N octadecylammonio]-butane-1-carboxy1ate.

When other watersoluble inorganic alkaline builder salts, water-soluble organic alkaline builder salts, and mixtures thereof, replace, on an equivalent basis in whole or in part, the sodium tripolyphosphate used above in Examples IX and X, substantially equivalent results are obtained in that soil redeposition on fabrics is minimized; e.g.: the alkali metal tripolyphosphates, pyrophosphates, orthophosphates, perborates, hexaphosphates, sesquicarbonates, bicarbonates, amino polycarboxylates, and polyphosphonates. When in Examples IX and X above an alkali metal silicate replaces a portion of the sodium tripolyphosphate used (e.g., from about to about 15% by Weight on a total composition basis), substantially equivalent results are obtained.

What is claimed is:

1. A composition of matter having the formula OHZZOZ 11 wherein A is a positively charged component selected wherein R is an alkyl, aralkyl, alkar-yl, alkoxyalkyl, alkaryloxyalkyl, N-acylaminoalkyl, or cyclic alkyl group having from to 22 carbon atoms; wherein R R and R are each selected from the group consisting of (a) an alkyl group having from 1 to 3 carbon atoms, (b) a hydroxyalkyl group having from 1 to 3 carbon atoms, (0) phenyl, (d) benzyl, (e) a polyethenoxy group having from 1 to 50- repeating ethenoxy units, and (f) a polypropenoxy group having from 1 to 10 repeating propenoxy units; wherein Q is selected from the group consisting of nitrogen, phosphorus, sulfur, and sulfoxide; wherein y is 1 when Q is nitrogen or phosphorus and 0 when Q is sulfur, or sulfoxide; and (2) a quaternized heterocyclic nitrogen compound having a heterocyclic nucleus selected from the group consisting of pyridine, imidazoline, morpholine, pyrrolidine, pyrroline, piperidine, piperazine, indoline, imidazolidine, quinoline, in-

dole, pyrimidine, pyrazine, pyrrole and triazine quaternized by bonding with a member selected from the group consisting of alkyl, aralkyl, alkaryl, alkoxyalkyl, alkylaryloxyalkyl, N-acylaminoalkyl and cyclic alkyl groups having from 10 to 22 carbon atoms, hydroxyalkyl groups having from 1 to 3 carbon atoms, polyethenoxy groups having from 1 to 50 repeating ethenoxy units and polypropenoxy groups having 1 to 10 repeating propenoxy units, said heterocyclic nitrogen compound having one substituent selected from the group consisting of alkyl, aralkyl, alkaryl, alkoxyalkyl, alkaryloxyalkyl, N-acylaminoalkyl, and cyclic alkyl group having from 10 to 22 carbon atoms; wherein each Z is selected from the group consisting of hydrogen, carboxymethyl, sulfato, phosphate, phosphonomethyl, sulfoethyl, sulfopropyl, sulfohydroxypropyl, hydroxyethyl, acetyl, a polyethenoxy group having from 1 to 50 repeating ethenoxy units, and a polypropenoxy group having from 1 to 10 repeating propenoxy units; wherein p is n times the summation of the products of on and s; wherein it indicates the degree of polymerization and ranges from about to about 2000; wherein s is the average degree of substitution at the Z positions of substituents other than hydrogen, said degree of substitution for substituents resulting in a negative charge at the Z position ranging from about 0.1 to 2.0, and, said degree of substitution for substituents resulting in no charge at the Z positions ranging from 0 to about 2.9; and wherein oz is the net charge obtained with the groups substituted at the Z position.

2. Dodecyltrimethylphosphonium-carboxymethyl cellulose.

3. Methyldi(polyethenoxy)octadecylammonium cellulose acetyl sulfate.

4. Dodecyldimethylsulfoxonium-phosphonornethy1 cellulose.

5. Cetyltrimethylammonium-sulfohydroxypropyl cellulose.

6. Cetylpyridinium-carboxymethylhydroxyethyl lose.

7. Benzyldimethyl [methyl-4( 1,1,3,3-tetramethylbutyl) phenoxyethoxyethyl]ammonium-carboxymethyl cellulose.

8. Benzyldodecyldimethylammonium cellulose acetyl sulfate.

cellu- References Cited UNITED STATES PATENTS 3,230,031 1/1966 Welch 812G 3,346,325 10/1967 Bille et al. 8120 3,379,719 4/ 1968 Rulison 260231 3,393,969 7/1968 Wade et al 8-1162 3,488,139 l/197O Vullo 8120 OTHER REFERENCES Chemical Abstracts, volume 60, 'No. 6, Mar. 16, 1964, p. 7034c.

DONALD E. CZAJA, Primary Examiner R. W. GRIFFIN, Assistant Examiner US. Cl. X.R. 

